1. Field of the Invention
The present invention relates to an encryption communication system between computers, and more particularly, it relates to a method for encryption communication between user computers by using a shared encryption key therebetween.
2. Description of the Related Art
Recently, encryption communication using a shared encryption key is widely utilized in computer networks.
In such a network, each computer user previously registers his own password in a communication center of the network. The communication center issues an identification number and a key generating information to the user. Then, the user's computer generates a shared encryption key based on the identification number and the key generating information, and performs the encryption communication between the user's computer and another party's computer.
In encryption communication, various technical terms and modulo arithmetic are used in the calculation of a shared encryption key, e.g., "prime number(s)", "prime number for path", "product of prime numbers", "modulus number(s)" "password" "center identifying information", "key generating information" and "exponential calculation".
In the communication center, however, the above processes requires very complex and troublesome calculation, particularly, calculation of prime numbers for paths between user computers so that a large amount of time is required for generation of the shared encryption key between user computers as explained in detail below.